Fluid forces on a square cylinder in oscillating flows with non-zero-mean velocities
The unsteady forces on a square cylinder in sinusoidally oscillating flows with non‐zero‐mean velocities are investigated numerically by using a weakly compressible‐flow method with three‐dimensional large eddy simulations. The major parameters in the analysis are Keulegan–Carpenter number (KC) and...
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Published in | International journal for numerical methods in fluids Vol. 60; no. 1; pp. 79 - 93 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Chichester, UK
John Wiley & Sons, Ltd
10.05.2009
Wiley |
Subjects | |
Online Access | Get full text |
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Summary: | The unsteady forces on a square cylinder in sinusoidally oscillating flows with non‐zero‐mean velocities are investigated numerically by using a weakly compressible‐flow method with three‐dimensional large eddy simulations. The major parameters in the analysis are Keulegan–Carpenter number (KC) and the ratio between the amplitude and the mean velocities of the approaching flow (AR). By varying the values of KC and AR the resulting drag and lift of the cylinders are analyzed systematically at two selected approaching‐flow attack angles (0 and 22.5∘). In the case of the non‐zero attack angle, results show that both the drag and lift histories can be adequately described by Morison equations. However, Morison equations fail to correctly describing the lift history as the attack angle is zero. In addition, when the ratio of AR/KC is near the Strouhal number of the bluff‐body flow, the resulting drag is promoted due to the occurrence of resonance. Based on the results of systematic analyses, finally, the mean and inertia force coefficients at the two selected attack angles are presented as functions of KC and AR based on the Morison relationships. Copyright © 2008 John Wiley & Sons, Ltd. |
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Bibliography: | istex:16F2DB75555CD863A645967C7F4CC29610421940 ark:/67375/WNG-3TRVHS4F-7 ArticleID:FLD1881 National Science Council in Taiwan - No. NSC 96-2221-E-005-107 ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0271-2091 1097-0363 |
DOI: | 10.1002/fld.1881 |